Seawater can be used as fuel to propel micromotors say scientists in the US. This finding eliminates the need for external fuels by enabling the micromotors to harvest energy from their surrounding environment.
Joseph Wang and his colleagues from the University of California, San Diego, have designed micromotors that consist of biodegradable and environmentally friendly magnesium microparticles and a nickel–gold bilayer patch for magnetic guidance and surface modification. Typically, ‘other catalytic microscale motors rely upon hydrogen peroxide as an external fuel source, but this requirement impedes many important applications for such tiny motors,’ explains Wang. Instead, these micromotors are fuelled by seawater and rely on the hydrogen bubble thrust generated from the magnesium–water reaction. ‘They [the micromotors] display efficient and prolonged propulsion in chloride-rich environments, like seawater, owing to the chloride pitting corrosion processes. The presence of the gold bilayer also enhances the magnesium–water reaction and leads to efficient motion in seawater,’ says Wang.
Seawater-driven magnesium based Janus micromotors for environmental remediation
W Gao et al.
Nanoscale, 2013,5, 4696-4700